Passive infra-red sensor



FIG. 1 is a front view;

FIG. 2 is a rear view;

FIG. 3 is a right-side view;

FIG. 4 is a left-side view;

FIG. 5 is a bottom view;

FIG. 6 is a top view;

FIG. 7 is an isometric view; and,

FIG. 8 is an isometric view. 

The ornamental design for a passive infra-red sensor, as shown and described. 